The invention herein relates to a catheter and more particularly to a catheter for draining fluid from a patient's body while simultaneously providing a monitoring of temperature of the patient. More particularly, the temperature monitoring catheter herein is directed to a temperature monitoring urological catheter which can be inserted in the urinary tract of a patient for draining urine from the bladder while simultaneously providing a monitoring of such patient's temperature.
Urinary catheters for draining urine from a patient's bladder have been used as a diagnostic aid for measuring the urine output of a patient. The measurement of urine output enables the determination of kidney viability of the infirmed patient.
Generally, there are two types of urinary catheters. Such catheters are either simple catheters or balloon retention catheters which are commonly referred to as Foley catheters. The simple catheters, commonly called urethral catheters, are used in patients wherein long indwelling times are not required. The balloon retention catheters include an inflation lumen which extends around the proximal end of the catheter, which lumen can be inflated after it is positioned within the patient's bladder to form an inflated balloon structure. The inflated balloon retains the proximal end of the catheter in the patient's bladder to insure drainage of any urine buildup from the bladder. The retention catheters, in addition to having an inflatable balloon section, include an inflation lumen which communicates with the inflatable balloon. The inflation lumen is provided with a valve which can be actuated to either introduce fluid to the balloon or to withdraw fluid from the balloon to enable removal of the catheter from the bladder.
Whether a simple catheter or a balloon retention catheter is utilized, urinary catheters include a drainage lumen which extends along and through the shaft of the catheter. The drainage lumen opens at the proximal end of the catheter shaft through a drainage eyelet or opening, which eyelet or opening is positioned within the patient's bladder. Urine which collects in the bladder flows through the eyelet along the drainage lumen and out of the catheter through the distal end. The distal end of the catheter is generally connected to a drainage bag for collecting the urine and providing a means for measuring the volume of urine collected.
There is available a three lumen, temperature monitoring, urinary catheter which is a balloon retention catheter. One of the lumens in the catheter is a drainage lumen and a second lumen in the catheter is the inflation lumen. The third lumen in the catheter provides a path for an electrical lead which extends axially along the shaft of the catheter to the proximal end where a temperature thermistor is positioned. The tri-lumen catheter thus provides for detecting temperature as well as draining urine from a patient's bladder. One disadvantage with such a tri-lumen catheter is that in order to provide for three lumens in a catheter having a fixed French size, the diameter of the drainage lumen is reduced. Thus, the rate of draining is reduced. Alternatively, to maintain a drainage rate, the diameter of the catheter shaft can be increased, thus increasing the diameter of the drainage lumen. Increasing the shaft diameter can cause greater discomfort for the patient and is undesirable.
Another drawback of such a tri-lumen catheter is that with normal and expected movement of a catheterized patient, the natural friction between the wire and catheter causes kinking of the wire within the third lumen. Such kinking can lead to breaking of the wire which potentially can erode through the catheter and lead to possible damage to the patient's urinary tract. The kinking can also bring about displacement of the thermistor or proximal end of the catheter. In addition, kinking of the wire in the catheter can cause some discomfort to the patient.
It would be desirable to provide a catheter which can be used for draining fluids from a patient while simultaneously providing temperature monitoring and which avoids the drawbacks of the presently available design.